Passive Microstrip Research Articles

A Phase Shift-Based and Quadrant-Distinguishable Passive Microstrip Antenna Sensor for Metal Crack Detection

A Phase Shift-Based and Quadrant-Distinguishable Passive Microstrip Antenna Sensor for Metal Crack Detection

Passive RFID microstrip UV photosensitive sensor label based on MoS2/Co3O4/RGO nanocomposites

This study investigates a coreless radio frequency identification (RFID) photosensitive sensor tag that employs a nanocomposite material comprising molybdenum disulfide (MoS₂), cobalt oxide (Co₃O₄), and reduced graphene oxide (RGO). The photosensitive sensor tag exhibits commendable photosensitivity performance, which has been evaluated through comprehensive sensitivity, response characteristic, and stability testing. Upon exposure to UV irradiation at intensities of 20 mW/cm2 and 200 mW/cm2, the input return loss undergoes a change of 20.933 dB. Within the range of 20 mW/cm2 to 200 mW/cm2, the photosensitive sensor tag demonstrates a response time of 15.4 s and a recovery time of 30.6 s. These results provide compelling evidence that the MoS₂/Co₃O₄/RGO nanocomposite material, functioning as a photosensitive material, exhibits exceptional sensitivity, responsiveness, and repeatability.

Linearity–Nonlinearity-Separation FDTD Method for Nonlinearity Analysis of Passive Microstrip Circuits

Linearity–Nonlinearity-Separation FDTD Method for Nonlinearity Analysis of Passive Microstrip Circuits

Design and analysis of microstrip transceiver array antennas with the function to suppress beam deflection for 77 GHz automotive radar

A microstrip transceiver array antenna with high beam pointing accuracy is designed for automotive radar. Considering the influence of the lossy conductor on the excitation current, the beam deflection problem formed by the passive microstrip series-feed linear array is analyzed and solved. Compared with the traditional microstrip series-feed linear array, the microstrip series feeder array designed in this paper has good beam pointing accuracy. A power divider based on substrate-integrated waveguide (SIW) and microstrip line (MSL) with Chebyshev amplitude distribution(applied to the transmit array antenna) and binomial amplitude distribution(applied to the receive array antenna), respectively, is designed as the feeding network of the linear array. The fabrication and measurement of the prototype transceiver array antenna are completed to verify its beam directivity. The simulation and measurement results show that the E-plane main beam of the transceiver array antenna radiation pattern has good pointing accuracy, which makes the detection accuracy of the automotive radar significantly improved.

Rethinking Liquid Crystal Tunable Phase Shifter Design with Inverted Microstrip Lines at 1–67 GHz by Dissipative Loss Analysis

Growing 5G/6G phased-array beam-steering applications, for which liquid crystal (LC) is one of the enabling technology candidates, have sparked interest in the modulation of the phase (and amplitude) of microwave and millimeter-wave signals. In this communication, fresh insights into the systematic design analysis of a 1–67 GHz passive inverted microstrip line (IMSL) phase shifter filled with highly anisotropic LC as tunable dielectric media are obtained. Based on waveguide disturbance tests to characterize the dielectric properties of the non-tunable PCB and tunable LC used in the IMSL phase shift device filled with a GT3-24002 LC layer (125 µm thick) partially enclosing a 220 µm wide, 17 µm thick, 1.35 cm long copper core line, a 0–π differential phase shift in the 1–67 GHz range with less than 2 dB insertion loss is reported. Dissipative loss analysis shows that the dielectric absorption of the LC is 21.28% of the input signal power at 60 GHz. Further investigation is performed to quantify the impacts of dielectric substrate thicknesses (PCB and LC) on the wave-occupied volume ratio (and hence the phase tuning range), as well as on dissipative losses (including conductor loss and dielectric loss). Specifically, conductor loss is observed to follow a linear relationship with the reciprocal of the LC thickness.

Passive RFID microstrip photosensitive sensor based on TiO2/rGO/CuO composite

In this paper, a passive RFID microstrip antenna photosensor based on titanium dioxide (TiO2)/reduced graphene oxide (rGO)/copper oxide (CuO) nanocomposite was designed and fabricated for monitoring light intensity in the environment. The microstrip patch antenna with slot is designed by HFSS simulation, the actual antenna is prepared by the engraving machine, and the photosensitive RFID sensor is prepared by coating the nano-material on the antenna by drop coating. The amplitude of ambient light intensity is determined in the frequency band of 2.082 GHz–2.087 GHz. To study its performance, the sensor coated with the sensitive material was tested under a solar simulator. The results show that from the dark environment (0 klx)-32.9 klx light intensity, the sensitivity of the photosensor is 0.106 ± 0.03 db/klx, and the sensitivity is 0.784 ± 0.08 db/klx under the light intensity of 36.8–53.9 klx. The response time of the photosensor was 20.1 s and the recovery time was 30.3 s in the light intensity range of 0–53.9 klx, indicating that the TiO2/rGO/CuO composite has good responsiveness and repeatability as a photosensitive material.

A Review on the Structure, Application and Performance of the Passive Microstrip Devices

Microstrip technology is widely applied for design and implementation of several communication devices such as filters, diplexers, triplexers, multiplexers, couplers, etc. They are utilized to isolate desired signals and remove disturbing signals. The layout of filters, diplexers and triplexers have two, three and four ports, respectively. Passive filters have at least one pass channel, whereas diplexers have at least two channels to transmit the desired signal, and multiplexers have more passbands with more channels. In order to implement the passive components, first a cell called resonator must be designed. Creativity is very important in resonator design. It must be small and novel to get a better device than previous works. Therefore, the layout of previous reported resonator, used in passive microstrip devices, are studied in this work. There is a fierce competition among designers to miniaturize and increase the device performance. Hence we will investigate them, from the point of view size and performance, in this work. Some diplexers are multi-channel, which are more difficult to design than two-channel diplexers. Therefore, the multi-channel diplexers are less reported than the two-channel diplexers. The design of multiplexers is also very difficult because several channels must be controlled. Hence, they are less designed than filters and diplexers. The diplexers can be bandpass-bandpass or lowpass-bandpass, where the latest is less designed. This is because designing a lowpass-bandpass diplexer needs lowpass and bandpass resonators, whereas the design of a bandpass-bandpass diplexer needs only a bandpass resonator.

On Improved-Reliability Design Optimization of High-Frequency Structures Using Local Search Algorithms

The role of numerical optimization has been continuously growing in the design of high-frequency structures, including microwave and antenna components. At the same time, accurate evaluation of electrical characteristics necessitates full-wave electromagnetic (EM) analysis, which is CPU intensive, especially for complex systems. As rigorous optimization routines involve repetitive EM simulations, the associated cost may be significant. In the design practice, the most widely used EM-driven procedures are by far local (e.g., gradient-based) ones. While typically incurring acceptable expenses that range from dozens to a few hundreds of objective function evaluations, they are prone to failure whenever a decent initial design is not available. Representative scenarios include simulation-based size reduction of compact devices or re-design of structures for operating/material parameters being distant from those at the available design. A standard mitigation approach is the involvement of global search methods, which entails significantly higher computational costs. This paper reviews the recent methodologies introduced to improve the reliability of local parameter tuning algorithms without degrading their computational efficiency. We discuss frequency-based regularization, adaptively adjusted design specification approach, as well as accelerated feature-based optimization. All of these techniques incorporate mechanisms that improve the performance of the search process under challenging scenarios, primarily poor initial conditions. The outline of the mentioned methods is accompanied by illustrative examples including passive microwave circuits and microstrip antennas. Benchmarking against conventional local search is provided as well. Furthermore, the paper discusses the advantages and disadvantages of the reviewed frameworks as well as speculates about future research directions.

Experimental Time-Domain Study for Bandpass Negative Group Delay Analysis With Lill-Shape Microstrip Circuit

This paper focuses on the time-domain analysis of bandpass (BP) negative group delay (NGD) function. The innovative NGD investigation is based on the time-domain experimentation of an innovative topology of “lill”-shape passive microstrip circuit. The design principle of the proof of concept (POC) constituted by particular microstrip shapes is described. The NGD circuit is inspired from a recent fully distributed “li”-topology. Before the time-domain investigation, the BP NGD specifications of the circuit under study are academically defined. As practical application of the basic definition, a frequency domain validation of “lill”-circuit is presented in the first section of the paper. The POC circuit is specified by a -8 ns NGD value at 2.31 GHz NGD center frequency and a 27 MHz NGD bandwidth. The “lill”-circuit exhibits an attenuation loss of about -6.2 dB at the NGD center frequency. Then, the two-port black box model of “lill”-NGD-circuit represented by touchstone data of the measured S-parameters is exploited for the transient simulation. The measured group delay (GD) illustrates that the tested “lill”-circuit operates as a BP function regarding the NGD with NGD equal to -8.1 ns at the NGD center frequency. The time-domain demonstration of the BP NGD function was performed using a gaussian pulse modulating sine carrier. The innovative experimental setup with the possibility to plot simultaneously well synchronized input and output signals is explained. The BP NGD time-domain response is understood from commercial tool simulation using the touchstone S-parameters of the measured “lill”-circuit by using a Gaussian up-converted pulse having a 27 MHz frequency bandwidth. It was observed that the output signals are delayed when the sine carrier is out of NGD-band. However, the output signal envelope is in advanced of about -8 ns when the carrier is tuned to be approximately equal to the 2.31 GHz NGD center frequency. To confirm the time-domain typical behavior of BP NGD response, an input pulse signal having Gaussian waveform were considered during the test. However, the input signal spectrum must be determined in function of the NGD bandwidth. After tests, measured output signal envelopes presenting leading edge, trailing edge and peak in time-advance compared to the input ones are observed experimentally. The results of the present feasibility study open a potential microwave communication application of BP NGD function notably for systems operating with ISM and IEEE 802.11 standards.

Design of Open-circuited Stub Butterworth Low-pass Microstrip Line Filter

This article designs a novel 2.5GHz Butterworth low pass microstrip line filter (MLF) by PCB prototyping machine. We could realize the theory, implement, and application of MLF in the same time .we design and simulate MLF circuit by IE3D software package. We choose FR-4 glass fiber PCB to make the MLF. We measure the S parameter frequency response of MLF by vector network analyzer.

Interconnect Routing for Large-Scale RSFQ Circuits

The increasing complexity of modern rapid single flux quantum (RSFQ) circuits has made on-chip signal routing, an issue of growing importance. In this paper, several methods for routing large-scale RSFQ circuits are described, and a process is presented for determining when to use passive microstrip transmission lines (PTL) and active Josephson transmission lines (JTL). The effect of the size of the JTL inductor and Josephson junctions on the length of a JTL chain for a target delay is also discussed. The dependence of the JTL inductance on the physical layout is evaluated, and the effects of the primary PTL parameters on delay are characterized. A novel PTL driver and receiver configuration is also proposed. Tradeoffs among the number of JJs, inductance, and length of a PTL stripline in the receiver and driver circuits are reported. The energy dissipation is evaluated for two different interconnects. A tradeoff between the proposed PTL circuits and an optimized JTL in terms of energy dissipation and delay is discussed. Guidelines for choosing the optimal element values are determined, and a simulated bias margin of ±29% for the bias current of the proposed receiver operating at 20 GHz in a 10 kA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> technology for a 1-mm transmission line is achieved. Summarizing, guidelines and design tradeoffs appropriate for automated layout and synthesis are provided for driving long interconnect in SFQ VLSI circuits.

Design of an Ideal Low Pass Microstrip Line Filter Using the Defected Ground Structure

A design and simulation for low pass microstrip line filter with defected ground structure has been researched, the main purpose is with the simplest method to design an ideal low pass filter. In this paper, simulated soft (Ansoft HFSS V.6.0) used to be simulated the frequency response under different geometric shape of DGS. The results show good performance of a low pass filter with DGS. Final, a low pass filter with DGS design and fabricated, The properties are shown as flow: center-frequency: 7.28G, S21:-47dB, cut-off frequency: 5.88GHz.

Compact wideband band pass microstrip filter loaded by triangular split ring resonators

AbstractA compact wideband band‐pass microstrip filter based on triangular split ring resonators is presented. The center frequency of the proposed structure is 3.1 GHz and the 3 dB bandwidth results 1.05 GHz. Good agreements between the simulated and measured results demonstrates the effectiveness of the proposed design. The size of the filter is 14 × 50 mm2 only.

Non‐unicity of the electric near‐field planar emission model with dipole array

This study deals with the behavioural modelling of the planar electric- (E-) near-field (NF) emission from electronic printed circuit boards. The methodology indicating how to synthesise the model from the given scanned E-NF maps in the observation plane of interest is established. The modelled radiation source is built with exclusively E-dipole array whose components are determined by the inverse method. After computational routine algorithm Matlab implementation, the proposed model was validated with various demonstrators. Relevant verifications were performed at different operating frequencies with the E-NF emission from analytical radiation, measurement scanning with active complex RF PCB and full wave simulation with microwave passive microstrip structure. It was shown that the model enables to reproduce the equivalent source with relative error vector magnitude accuracy less than 3%. The error analyses in function of the distance between the observation plane and the radiating PCB were proposed. Moreover, the non-unicity and limit of the model with the E-field emission prediction from different E-field radiated data defined in the scanning observation surface plane positions from the radiating circuit. The developed model can be potentially used to lower the cost of EM compatibility engineering during the electronic PCB design phase.

Time-Domain Magnetic Dipole Model of PCB Near-Field Emission

A magnetic dipole array based time-domain (TD) modeling of electromagnetic near-field (NF) radiated by printed circuit boards (PCB) is introduced. The behavioral equivalent model of radiated emission using elementary magnetic dipoles compliments the previously described TD model using electric dipoles. The equivalent dipole model parameters are determined by the matrix inversion method from the time-dependent magnetic NF data. The proposed modeling approach was implemented in MATLAB. As a proof of concept, the TD magnetic NF radiated by a passive microstrip test PCB exited by a nanosecond-duration signal was considered. The modeled-magnetic NF maps were compared with the reference data in the observation planes situated at some centimeters above the tested PCB, showing good agreement. The comparison between magnetic and electric dipole models was performed, showing the advantage of the latter.

Design of defected ground low pass microstrip filters with enhanced performance characteristics

Design of defected ground low pass microstrip filters with enhanced performance characteristics

Confirming the Signal Integrity in Transmission of Digital Signals on Microstrip Straight Circuits via the Eye Diagrams

Because of the high volume of processing, transmission, and information storage, electronic systems presently requires faster clock speeds tosynchronizethe integrated circuits. Presently the “speeds” on the connections of a printed circuit board (PCB) are in the order of the GHz. At these frequencies the behavior of the interconnects are more like that of a transmission line, and hence distortion, delay, and phase shift- effects caused by phenomena like cross talk, ringing and over shot are present and may be undesirable for the performance of a circuit or system.Some of these phrases were extracted from the chapter eight of book “2-D Electromagnetic Simulation of Passive Microstrip Circuits” from the corresponding author of this paper.

Validating Some Signal Integrity Procedures for Transmission of Digital Signals on Microstrip Circuits

Because of the high volume of processing, transmission, and information storage, electronic systems presently require faster clock to synchronize the integrated circuits. At present the speeds on the connections of a printed circuit board (PCB) are up to 4 GHz or even faster. At these frequencies the behavior of the interconnects are more like that of a transmission line, and hence distortion, delay, and phase shift-effects caused by phenomena like cross talk, ringing, and overshoot are present and may be undesirable for the performance of a circuit or system. Thus, the interconnects do not have to be considered like simple conductors or lumped elements. All this gives rise to a new emerging discipline known as signal integrity. In this discipline the correct timing and signal quality preservation preventing transients and false switching are studied in order to avoid excessive delays. These phrases were extracted from the chapter eight of book 2-D Electromagnetic Simulation of Passive Microstrip Circuits from the corresponding author of this paper.

High selectivity band pass filters on iso/anisotropic dielectric, ferrimagnetic, and metamaterial substrates

ABSTRACTThis work describes a frequency response investigation of a band pass microstrip filter geometry printed on different substrate materials. The filter geometry comprises a wavelength rectangular ring resonator that is side coupled to two quarter‐wavelength lines to provide the access ports. This filter geometry is particularly suitable for high‐frequency selective applications. The investigation of the properties of the filter geometry is carried out for iso/anisotropic dielectric, ferrimagnetic, and metamaterial substrates, for comparison purpose. Simulation and design are performed using Ansoft HFSS, a commercial software based on the accurate finite element method. Resonant frequency, return loss, insertion loss, and percent bandwidth results are compared and discussed, taking into account the effect produced by each material substrate on the filter performance. Prototypes of band pass filters on isotropic substrates are built and measured. Simulated and measured results are in agreement. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:201–206, 2014

Design and testing of high-speed interconnects for superconducting multi-chip modules

Superconducting single flux quantum (SFQ) circuits can process information at extremely high speeds, in the range of hundreds of GHz. SFQ circuits are based on Josephson junction cells for switching logic and ballistic transmission for transferring SFQ pulses. Multi-chip modules (MCMs) are often used to implement larger complex designs, which cannot be fit onto a single chip. We have optimized the design of wideband interconnects for transferring signals and SFQ pulses between chips in flip-chip MCMs and evaluated the importance of several design parameters such as the geometry of bump pads on chips, length of passive microstrip lines (MSLs) and number of corners in MSLs as well as flux trapping and fabrication effects on the operating margins of the MCMs. Several test circuits have been designed to evaluate the above mentioned features and fabricated in the framework of a 4.5 kA cm−2 HYPRES process. The MCM bumps for electrical connections have been deposited using a wafer-level electroplating process. We have found that, at the optimized configuration, the maximum operating frequency of the MCM test circuit, a ring oscillator with chip-to-chip connections, approaches 100 GHz and is not noticeably affected by the presence of MCM interconnects, decreasing by only about 3% with respect to the same circuit with no inter-chip connections.